Efficacy. It needs to pass through this before it gets to effectiveness testing. Meta studies are important for examining this hence the wiki section mention earlier, which lists a bunch.
Note that just being in the conversation doesn’t mean it’s not being cannibalised. Papers or trends may arise that put other researchers in a tizzy. If it’s an accepted practice, you are likely to see a lot of papers fine tuning methods.
The placebo thing shuffles it under their umbrella. There’s a lot of issues there with those.